The present disclosure relates to a vehicle seat fastening structure.
For example, in a vehicle seat arranged in an automobile or the like, a seat cushion forming the vehicle seat is mounted to a slide rail that is slidable in a seat front-rear direction. Specifically, a cushion frame forming a framework of the seat cushion is fixed to a movable rail of the slide rail with bolts and nuts (see Japanese Unexamined Patent Application Publication No. 2015-214329).
In some types of vehicles, a load sensor to detect an occupant's weight (a so-called “Occupant Classification Sensor (OCS)”) is provided between the movable rail and the cushion frame. To provide the load sensor, a specified space for arrangement of the load sensor is required between the movable rail and the cushion frame.
Also, if a collision from behind the vehicle occurs, the cushion frame is raised upward relative to the movable rail that is mounted to the vehicle body. In order to reduce an impact due to the raising of the cushion frame, it is necessary to arrange the nut provided to the cushion frame and a bottom wall portion of the cushion frame to be spaced apart from each other in an ordinary condition.
Thus, in order to provide a specific space between the movable rail and the cushion frame as well as between the nut and the cushion frame, a cylindrical spacer 105 is arranged between an upper surface 101A of a movable rail 101 and a nut 104 as shown in FIG. 7. In a fastener of FIG. 7, a bolt 103 and the nut 104 are screw-engaged with each other through the spacer 105, and thereby the movable rail 101 and a cushion frame 102 are fastened to each other.